Deep multilayer gratings with adjustable bandpass for spectroscopy and monochromatization

We propose here a deep multilayer grating with an adjustable bandpass as an alternative dispersive element for use in x-ray spectroscopy and monochromatization. When making a multilayer grating, we remove part of the reflecting planes of a multilayer, allowing radiation to penetrate deeper. Since the resolution, or the bandpass, is reciprocally proportional to the penetration depth, we improve the resolution and reduce the bandpass of a simple multilayer mirror without affecting the reflectivity. By changing the grating land/period ratio, the amount of the removed material can be continuously varied and, thus, the extinction depth and the bandpass, or resolution, can be continuously varied. In this way we can find an optimum between required resolution and flux for a particular application. (C) 2002 American Institute of Physics.